After months of requests, he has granted us permission to visit one of America's newest and most secret establishments: the National Counterterrorism Center, the NCTC.

It is a nondescript building, but inside is the beating heart of America's counter-terrorism nerve centre.

"This is where we maintain a 24-hours-a-day, seven-days-a-week operational watch in the counter-terrorism intelligence community and monitor situational awareness in the world of CT [counter-terrorism]," says Vice Admiral Don Loren, one of the watch officers in the Operations Room.

The Operations Room is a large open-plan chamber filled with desks and computer terminals.

It is here in this room three times a day, every day, that America's specialists in counter-terrorism gather to share information

But today it is almost empty. Because we are media, all the undercover agents from the Federal Bureau of Investigation, the National Security Agency and the Central Intelligence Agency who would normally sit here have been moved out of sight.

But up on the wall is a giant plasma screen showing every plane approaching the United States.

"Right now, you're looking at the Eastern Seaboard air corridor, and we use that to monitor events of special interest and to keep an eye should there be any reports of what we call no-fly activity," Vice Adm Loren says.

A "no-fly" means a plane with a passenger suspicious enough that the flight can even get turned back over the mid-Atlantic.

In everyone's minds is the thought: "9/11, never again."

Enormous data flow

The NCTC is also intended to remedy the sort of information blockages that led to 9/11.

When it was set up two years ago, they brought in the "imagineers" from Hollywood - experts on sharing information.

The movements of every plane approaching the US are monitored

The data flow here is enormous: more than 6,000 reports come through every day from satellite, electronic and human intelligence sources.

When an incident happens, a "terror line" is created to pass the information to everyone who needs it.

Central to all this is the Briefing Room, where screens rise up like something out of a James Bond film.

This is the nerve centre of the US-led global "war on terror".

It is here in this room, three times a day, every day, that America's specialists in counter-terrorism gather to share information.

Obviously you want to stop an attack, but you don't want to stop an attack just in the nick of time

Vice Admiral Scott Redd

It brings in 16 agencies like the FBI, the CIA, Homeland Security as well as the White House, and has been described as a "stock exchange" for counter-terrorism intelligence.

The man in charge is almost unknown, yet he has one of the most sensitive jobs in the world.

Vice Admiral Scott Redd gives the president America's war plan on fighting terrorism.

"We take that, we've created an electronic library, we have over six million pieces of CT info that can be accessed by over 6,000 counter-terrorism analysts around the world.

Vice Adm Redd gives the president the war plan on fighting terrorism

"So bringing that together has been very significant."

But I put it to Vice Adm Redd that although America itself had not been attacked since 9/11, al-Qaeda-inspired terrorism appears to be as active as ever.

Did America's strategy go any deeper than tackling the symptoms?

"Obviously you want to stop an attack, but you don't want to stop an attack just in the nick of time," the NCTC director replied.

"You want to go after, you sort of work your way back, ultimately all the way back to the radicalisation/recruitment phase, proselytisation, with things like travel, the finances which underpin it, training, leadership, planning, typically more travel and then everything up to and including stopping the attacks."

The NCTC has 400,000 names in its database here.

It has five watch teams working 12-hour shifts and a vast electronic library.

But of course, despite all the technology and resources, none of this is guaranteed to stop terrorism.

Senior officials here admitted that this war could last another 40 years or more, and there will be defeats along the way.